Screening of Nitrogen High-Efficiency Varieties and Comprehensive Evaluation of Nitrogen Efficiency of Sea Island Cotton
In order to screen nitrogen-efficient sea island cotton varieties,supplement the harvest screening indexes and improve the cotton nitrogen efficiency evaluation system,three nitrogen fertilizer treatments of low nitrogen(0 kg/ha,N0),medium nitrogen(240 kg/ha,N1)and high nitrogen(480 kg/ha,N2)were set up to comprehensively evaluate the type of nitrogen efficiency of the sea island cotton,screen out nitrogen-efficient sea island cotton varieties,and determine the evaluation indexes for screening nitrogen-efficient sea island cotton varieties in harvesting period by correlation analysis,principal component analysis and subordinate function analysis using 12 sea island cotton varieties bred in the past 20 years.The results showed that the coefficient of variation of most of the indicators of the sea island cotton varieties for testing under different nitrogen fertilizer levels were greater than 10％,and the 19 evaluation indicators were subjected to principal component analysis.Under N1 and N2 levels,the cumulative contribution rate of the four principal components were 86.68％and 88.03％,respectively.Among the four principal components,12 indicators,such as plant height,number of fruiting shoots,stem and leaf biomass,reproductive organ biomass,etc,accounted for a large proportion of the four principal components,and the indicators were significant(P＜0.05)or extremely significant(P＜0.01)positive correlation.Based on the comprehensive score of the principal components,the comprehensive evaluation value of nitrogen efficiency and lint yield,one nitrogen-efficient variety,three nitrogen-medium-efficient varieties and three nitrogen-low-efficient varieties were screened out.In summary,Miancheng 10 was identified as a nitrogen-efficient variety,and it was concluded that SPAD,reproductive organ biomass,reproductive organ nitrogen accumulation,total aboveground nitrogen accumulation,number of bolls per plant,seed cotton yield,lint yield,and nitrogen fertilizer agronomic utilization rate could be used as the core indexes for the screening of nitrogen-efficient varieties.
Sea island cottonNitrogen efficiency evaluationVariety screening
NETL
NSTL
万方数据
